In order to get more relevant error messages, try to install the app using your desktop iTunes and then sync via USB cable to see what the iTunes desktop app error messages are. Usually they will point you in the right direction.

iTune doesn't show any error message after the synchronization was completed. Everything works like there is no problem. It looks like the problem is in the IPA package because the app was transferred to the device but the device doesn't accept it.

or do I need another way to find error message in iTune app?

I already uninstall both Flash Builder 4.6 and AIR for IOS with uninstaller in 'Application/Utilities/', then reinstall again, the problem still exists

Thankyou for the info about creating new certs. It's fixed the issue I was also having trying to debug on an iPad. Insanely annoying having an app just refuse to deploy with NO message, NO error, NO reason.

in xcode you can check the organizer window under the window menu, when u are installing the app it show debug messages under your device -> console option, there it say it has signature problems, hope that helps!